Fabrication of a modified and flexible plastic-based graphite electrode and its application for determination of some drug compounds in biological samples

In the recent years many efforts have been focused on the miniaturization and pliability of electrochemical systems for use in electrochemical sensors, biosensors or energy storage devices using inexpensive, inert and flexible substrates for fabrication of electrodes with desired shapes including plastic or paper [1, 2]. Carbonaceous materials like carbon nanotubes, carbon black and graphite are the most attractive choices for these applications because of the ease at which the electrode can be prepared, its stability and also good electrochemical properties of carbon including high conductance and chemical inertness which can be further modified by different modification techniques for achievement of a good and reliable electrochemical signal toward analytes [3]. There are many reports in the field of the home made plastic or paper-based electrodes for electronic, electrochemical or wearable devices [3-5].Herein we demonstrate the fabrication of a modified graphite electrode with desired shape and size based on a non-conductive plastic substrate which can be used in various electrochemical applications. The electrode was activated using electrochemical pretreatment and some modifications were performed for achievement of high surface area and electrocatalytic activity toward analyte determination. The effects of some parameters including pH and scan rate on the electrode response were studied and optimized. The prepared electrode was used for determination of some drug components in pharmaceutical preparations and real biological samples. Linear calibration curve and low limit of detection obtained. The efficiency of method was further evaluated with recovery experiments. Results showed the suitability of prepared electrode in the fast, inexpensive and accurate electrochemical determinations.